The present invention relates to a chuck unit, which is suitable for inserting a plurality of workpieces into a receiving portion in a direction parallel to the major surfaces of these workpieces in an aligned manner.
FIGS. 1 and 2 show a conventional four-element ladder-type filter. This filter comprises two series ceramic resonators 2 and 3, two parallel ceramic resonators 4 and 5, an input terminal plate 6, a ground terminal plate 7, an output terminal plate 8, an internal connection terminal plate 9 and a plate spring 10, which are stored in a box-type case 1. Outlines of these inner parts are substantially equivalent to each other. FIG. 3 is a circuit diagram showing the electrical connection thereof.
The input terminal plate 6 is provided on its one major surface with a protruding portion 6a which is in pressure contact with a central portion of the series resonator 2. The ground terminal plate 7 is provided on both of its major surfaces with protruding portions 7a and 7b which are in pressure contact with central portions of the two parallel resonators 4 and 5 respectively. The output terminal plate 8 is provided on both of its major surfaces with protruding portions 8a and 8b which are in pressure contact with central portions of the parallel resonator 5 and series resonator 3 respectively. The internal connection terminal plate 9 has a portion 9a which is inserted between the series resonator 2 and parallel resonator 4, a portion 9b which is arranged next to an outer major surface of the series resonator 3, and a coupling portion 9c which connects these portions 9a and 9b. Since the plate spring 10 is interposed between the portion 9b and an inner side surface of the case 1, the terminals 6-9 and the resonators 2-5 are in pressure contact with each other to be electrically connected.
A cover sheet 11 is inserted in an opening of the case 1, and a cavity which is defined by the cover sheet 11 and the opening is filled up with filler 12 such as resin, thereby the opening of the case 1 is sealed. Lead portions 6b, 7c and 8c of the input terminal 6, the ground terminal 7 and the output terminal 8 protrude through the cover sheet 11 from the opening of the case 1.
When the filter having the aforementioned structure is assembled in a conventional manner, the parts 2-5 and 6-10 are manually inserted one by one with tweezers in the case 1. Therefore, the working efficiency of the conventional manual insertion is quite low. In order to improve this working efficiency, it may be desirable to automatically assemble this filter by a chuck unit, such as a robot or the like.